A novel adaptive quantization method for video coding

Abstract

In this paper, we propose a novel AQ (Adaptive Quantization) algorithm to improve the subjective coding performance. Firstly, the factors affecting a suitable adaptive quantization method are carefully analyzed. Two important conclusions are drawn to guide designing a suitable AQ method. Secondly, based on the drawn analysis, a novel SATD (Sum of the Transformed Difference) based temporal adaptive quantization method is proposed. The proposed method fully considers the temporal characteristics, which can produce more visual-friendly QP (quantization parameter) offset distribution. Experiments are performed on x264 and HM16.0, respectively. With SSIM (Structure Similarity) as the metric, more than 21.07% BD-Rate (Bjontegaard-Delta Rate) saving can be achieved on x264, and on HM16.0, 8.07% and 7.99% BD-Rate savings can be obtained for LDP (Low-Delay-main-P) and LDB (Low-Delay-main-B) configurations, respectively, which is better than the state-of-the-art methods.